1. Field of the Invention
The present invention relates generally to telephony, and more particularly to testing a connection in a telephone network.
2. Related Art
In a modern telephone network, the need often arises to evaluate the condition of the network. Typically, this evaluation takes place one connection at a time. Two endpoints are selected, thereby defining the connection. Test equipment is then deployed to one of the endpoints. In order to properly evaluate the connection, however, it is necessary to control the conditions imposed on the connection by the other endpoint.
In a conventional telephone network test method, a network switch is selected as one endpoint of the connection to be tested, and a particular telephone is selected as the other end of the connection. The selected switch is typically located in a central office of the network provider. In order to test the connection between a particular telephone and the selected switch, a technician with test equipment is dispatched to the location of the telephone. The technician connects the test equipment to the telephone and dials the selected switch to establish the connection to be tested.
In order to control the conditions imposed upon the connection by the switch end of the connection a device known as a test responder is connected to the selected switch. In order to impose a particular condition on the connection to support a particular test, the technician may, for example, dial a particular number that causes the test responder to impose the particular condition on the connection.
A primary disadvantage of this approach is that a connection cannot be tested end-to-end, that is, between one termination and another. At most, a connection can be tested between one termination and a test point within the telephone network, such as a switch.
Another disadvantage of this approach is that connections to particular telephones can only be tested by sending a technician to the location of the telephone. This arrangement imposes significant costs on the network provider, and inconveniences the user of the telephone, who must rearrange his schedule to accommodate the technician.
The present invention is a system and method for testing a connection in a telephone network using an interactive telephone response module (ITRM). The ITRM enables a user to impose selected conditions on a telephone line. In another embodiment, the ITRM is connected between the handset and station set of a telephone terminating one end of the connection to be tested. In another embodiment, the ITRM is connected between the telephone network and the station set of a telephone terminating one end of the connection to be tested.
In one embodiment, the ITRM includes three switches, each for imposing a different condition on the telephone line, also referred to herein as a xe2x80x9cconnection.xe2x80x9d A xe2x80x9csilencexe2x80x9d switch disconnects the telephone handset or station set from the connection and can terminate the connection to a xe2x80x9csilence circuit.xe2x80x9d This operation eliminates ambient noise produced by the telephone handset. This condition can be used to facilitate the measurement of line noise, also known as xe2x80x9cquiet channel noisexe2x80x9d and to test for and measure echo characteristics.
A xe2x80x9cloopbackxe2x80x9d switch is used to echo signals received over the connection being tested. The condition imposed upon the connection by this operation can be used to facilitate the measurement of the round-trip delay of a signal transmitted to the ITRM.
A xe2x80x9ctonexe2x80x9d switch is used to transmit a signal with known characteristics over the connection. In a preferred embodiment the known signal is a sinusoidal signal of predetermined amplitude and frequency. The condition imposed upon the connection by this operation can be used to facilitate the measurement of line loss.
In a preferred embodiment, the ITRM is used as part of an interactive telephone test system to test the connection between a telephone and a test point or other termination. An end-to-end connection test can be performed by choosing a connection termination as the test point. A test coordinator connected to the test point establishes a connection to the telephone. When the telephone user answers, a voice prompter in the test coordinator instructs the user to operate the ITRM to produce a desired condition on the connection. The telephone user operates the ITRM as instructed to produce the desired condition on the connection. The test module then measures characteristics of the connection under the desired condition. When the measurement is complete, the test coordinator ends the connection to the telephone.
One advantage of the present invention is that a connection can be tested end-to-end, that is, from one termination of the connection to another.
Another advantage of the present invention is that a telephone connection can be tested under predetermined conditions without sending a trained technician to the location of the telephone, or installing complex equipment at the location of the telephone. The ITRM can be provided to a telephone user with simple instructions for connecting the ITRM to the telephone. The connection can then be tested automatically with little skill or effort required of the telephone user.
Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.